1. Field of the Invention
The present invention relates to a car power source apparatus, and in particular to a car power source apparatus with a battery case that is connected to the car chassis ground via a ground line. The battery case houses a driving battery that drives the car, and monitoring and control circuitry for that battery.
2. Description of the Related Art
The car power source apparatus houses a driving battery and monitoring and control circuitry for that battery in a battery case. When the power source apparatus is installed on-board a car, it is necessary for the battery case to be reliably connected to the car chassis ground. This is for detecting driving battery leakage current, and for reducing monitoring and control circuit noise levels. The battery case can be directly attached to the car chassis with fasteners such as bolts to connect the battery case to the car chassis ground. However, since coatings are applied to car chassis surfaces, a stable and reliable electrical connection may not always be achieved in a configuration directly attaching the battery case with bolts. Further, for a battery case made of aluminum to reduce weight and attached to the chassis via bolts at a plurality of locations, metal corrosion can develop as a result of galvanic corrosion. These drawbacks can be resolved by connecting the battery case to the chassis via a ground wire (Refer to Japanese Laid-Open Patent Publication No. 2008-139249).